1. Field of the Invention
The present invention relates generally to media storage, and more particularly to a media storage system that allows media to be stored in and transferred among a plurality of media storage libraries.
2. Related Art
The advent of low cost, high powered computing systems has led to an expansion of their application in business and industry. As computing systems have become heavily relied upon to handle all facets of business and industry, the data storage requirements of these systems have grown dramatically. In an effort to contain data storage costs, system developers began to provide low cost data storage alternatives.
One early alternative was the paper tape storage medium. In this alternative, holes were punched into a paper tape, and the tape read by an optical reader. This eventually evolved into the use of magnetic tapes to store large amounts of data. Early magnetic tape storage systems required an operator to mount tapes onto a tape drive so the computer could access the tape.
Automated magnetic tape storage libraries were introduced to provide rapid access to a large number of magnetic tapes. Such systems utilize a robotic arm to retrieve a magnetic tape (housed in a cartridge) and mount the tape in a tape drive. One such automated storage system is the ACS4400 library system available from Storage Technology Corporation in Louisville, Colo., 80028.
These automated media storage libraries are available in a number of different configurations to meet a variety of storage needs. However, in many situations, the ability to reconfigure or expand the library to meet the dynamics of data storage demands is limited.
Additionally, as the storage volume requirements increase, the size of the storage system increases as well. Because of the large size of these automated systems, the robotic arm may be required to travel a relatively large distance to retrieve a cartridge to be loaded into a tape drive. This latency results in a longer average data access time and thus hinders system performance.
A further disadvantage of these automated systems is that a single robotic arm means that only one tape can be manipulated (mounted or unmounted) at a given time. Although some systems now have double-ended robotic arms, the ability to do cartridge retrieval operations in parallel is still somewhat limited.